1. Field of the Invention
The present invention relates generally to power applications and, more particularly, to a system and method for enabling power applications over a single communication wire pair.
2. Introduction
Power over Ethernet (PoE) (also known as inline power and phantom power) specifications such as IEEE 802.3af (PoE) and 802.3at (PoE Plus) provide a framework for delivery of power from power sourcing equipment (PSE) to a powered device (PD) over Ethernet cabling. Various types of PDs exist, including voice over IP (VoIP) phones, wireless LAN access points, Bluetooth access points, network cameras, computing devices, etc.
Conventionally, the PoE and PoE Plus specifications are designed to work on two-pair cabling using a pair of transformers in the PSE and the PD. PoE is capable of running over a worst case of 100 m on two pairs of Cat 3 cabling and PoE Plus is capable of running on a worst case of 100 m on two pairs of Cat 5 cabling. Implementations of PoE and PoE Plus include multiple instantiations for example over all four pairs. Non-standard four-pair as well as two-pair implementations also exist.
Current specifications do not address certain applications such as those that exist in older buildings that contain one-pair wiring. What is needed therefore is a mechanism that enables the transmission of high-speed data and power over one-pair wiring using a single transformer near the PSE and the PD.